The present invention relates to methods for enhancing the color of gemstones and to novel colored gemstones produced by invention methods.
A variety of materials having the physical and aesthetic properties desirable for use as gemstones are widely available. However, many of these materials but do not always have an aesthetically pleasing appearance. A variety of procedures have been employed in the art to improve the physical and/or aesthetic properties of minerals, e.g., electron beam irradiation, Cobalt-60 irradiation, neutron bombardment, exposure to intense heat, and the like.
More recently, the inventor herein developed a process for enhancing a minerals usable as gemstones by subjecting a combination of a gemstone and at least one form of cobalt metal or cobalt oxide to conditions suitable to enhance the color of said gemstone, without causing a significant level of surface damage to said gemstone. U.S. Pat. No. 5,888,918 was issued to cover said process. Using said process chrysoberyl, garnet, sapphire and topaz were modified to have colors in the spectrum of from light green to dark blue, depending on the gemstone, the treating agent(s) and treating conditions employed. Quartz was modified to have a light pink to a dark pink color using the same cobalt metal/oxide process.
Although the methods of the prior art have been able to produce colors in gemstones ranging from green to blue, none of the state of the art processes have been able to produce gemstones outside the green to blue spectrum except with quartz. And specifically, treatment of the gemstones with cobalt and/or cobalt oxides prevent obtaining gemstones in the color of the present invention. In addition, the treatment process of the current invention results in gemstone enhancement occurring in a far shorter time period.
Therefore, it would be desirable to be able to readily impart predictably enhanced and/or modified colors to materials useful as gemstones employing readily practicable methods which do not suffer from the drawbacks of prior art methods and which produce other colors.
In accordance with the present invention, methods have been developed for enhancing the color of minerals useful as gemstones. The methods include the process of subjecting the gemstones to a selected temperature while in the presence of a form of a selected metal, or metal oxide, such copper/copper oxide, for a selected period of time. Invention methods are relatively inexpensive to carry out, avoid the use of hazardous materials, and require no specialized equipment.